<p>Cell-penetrating peptides (CPPs) have been shown to have superior material transport ability because poor infiltration of activated lymphocytes into tumors is one of the crucial factors limiting the therapeutic effect of tumor immunotherapy. Numerous studies have investigated the potential application of CPPs in tumor immunotherapy. This review delves into the crucial role that CPPs play in enhancing tumor immunotherapy, emphasizing their impact on various immunotherapy strategies, such as cytokine therapy, adoptive cell therapy, cancer vaccines, and immune checkpoint inhibitors. We also discuss the practical application challenges associated with enhancing the efficiency of CPPs in terms of their stability and targeting ability. In conclusion, the combination of CPPs with tumor immunotherapy is a promising strategy that has potential for precision administration and requires further research for optimal implementation.</p>